Reversible internal combustion engine



9, 1939- E. o. P. THEGE ET AL 2,157,578

REVERSIBLE INTERNAL COMBUSTION ENGINE Filed April 25, 1956 2 Sheets-Sheet l 91K smmwa v/m V55 May 9, 1939. E. o. P. THEGE ET AL REVERSIBLEINTERNAL COMBUSTION ENGINE Filed April 23, 1936 2 Sheets-Sheet 2Patented May 9, 1939 EdvinOssian 1 INTIENAL COMBUSTION ENG .lhege andJohn Henry Percival wliliamllllhll, Stockholm. Bwedemaflgnorsuuamumssunmmsm 'muamsuuss. mam

Janine.

Means hitherto used for direct reversal of internal combustion enginesby means of compressed air have the disadvantage that it has not beenpossible to elect the reversal in a suiiiciently short space of time.This is due to the fact that, in reversing the direction of motion, ithas been necessary first to place the control lever in the stop positionand to let the engine come to a stop before the admission oi compressedair for the purpose of starting the engine in the opposite direction.Ii. this is neglected it may occur that the engine continues itsmovement in the same direction which will cause further delay or dangerand losses of compressed air. In such a case, distance or remote controlhas generally not been feasible as, at a distance, it is impossible todetermine when the engine has stopped and to determine the instant atwhich compressed air may be admitted for eflecting the reversal of theengine.

The present invention relates to a reversing mechanism for internalcombustion engines, by

the use of which the above mentioned diiiloulties are avoided and whichthus permits the reversal, i. e. the admission oi compressed air forchanging the direction of motion, to be effected immediately without thenecessity for waiting until the engine has stopped. Hence, the controllever is according to this invention moved directly from the forwardposition into the rearward position, or vice versa, without having firstto be placed in the stop position until the engine has stopped. Anarrangement of this kind has the advantage that the reversal takes placemuch more rapidly. and, besides, it may be used with remote control, inwhich case as mentioned above he who performs the operation has noopportunity of determining whether the engine has come to rest or not.

Some of the auxiliary apparatus used in reversing may be constructed inmany different ways, and thus the invention is not restricted to anyparticular design of this apparatus.

In order to explain more clearly the principle underlying the invention,there is illustrated in the accompanying drawings a suitable embodimentwhich will be hereinafter described.

Fig. 1 is a view partly in elevation and partly in section of a startingvalve and reversing valve arrangement embodying the invention.

Fig. 1a is a transverse cross-section on reduced scale taken generallyalong the lines la-la oi Fi 1;

Fig. 2 is a longitudinal cross-section showing on enlarged scale a partof the valve mechanism shown in Fig. 1;

Fig. 3 is a transverse cross-section through the valve mechanism shownin Fig. 2 and also shows in cross-section an engine exhaust valve.controlled thereby;

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l'ig.4isasectionsimiiartol"lg. Sshowing'tbe partsotthevalveotl'lgsdandtin a diii'erent position;

Fig. 5 is a section partly in elevation showing an engine cylinder withits associated starting and exhaust valves; and

Fig. 8 is a sectional view partly in elevation of the starting controlvalve shown in Fig. 1.

In said embodiment, Figure 1 illustrates previously known arrangementsfor supplying compressed air to the starting valves from a specialregulating member (distributing slide valve). These arrangements, withthe exception of a mechanism supplying compressed air to the exhaustvalves, are known for instance from the U. 8. Patent No. 1,886,234, and.therefore. they will here only be described in a summary way.

Each of the working cylinders of the engine is provided with a startingvalve I and all these valves are via pipes I and a common conduit 8communicating with an air admission valve 4. Valve 4-, to whichcompressed air is admitted through a pipe I from a suitable receiver(not shown), is provided with .a control lever I and communicates via apipe I with a housing I in which is located a distributing slide valveor sleeve 9. The valve case 8 and the distributingvalve are shown intransverse section on smaller scale in Fig..1a and it will be evidentfrom this transverse section that the case 8 communicates with all thestarting valves I through conduits I 0. The distributing slide valve 9is rotated in the one or the other direction, the rotary motion beingtransmitted from the crank shaft of the engine by means or a suitablegear comprising a gear wheel ll mounted on the slide valve shalt l2.Said shaft is driven at the same speed as the crank shaft, and the valve9 is slidably but not rotatively adjustable on the shaft II. Thedisplacement of the slide valve is eflected by means of a hand lever iswhich may be placed in the positions "ahead, stop and reve Theconnection between the hand lever l8 and the distributing valve 8 isformed by levers ll, l5 and a link it. The reversing operation of thearrangement above described has already been indicated in the foregoing.

. It need here only be stated that the compressed air distributed to thevarious conduits II by the distributing valve 9 is operative in thestarting valves I for opening these valves, so that starting air comingfrom the opened air admission valve I is supplied via the pipes 3 and 2at the right moment to each of the cylinders in a dennite order ofsequence.

In order to render possible more rapid manoeuvring than is possible withthe use of the arrangement above described, the cylinders oi the engineare, according to the present invention, provided with special exhaustvalves which,

when the piston is at the upper dead center, are opened in order todischarge into the atmosphere the compression air from the cylinders atthe end of the compression stroke. The opening of these exhaust valvesmay be eflected by means of compressed air which is admitted from aspecial distributi'ng'member, preferably in the form of a slide valve(32, Figs. 1, 2, 3 and 4), which may be driven from the previouslymentioned distributing slide valve 9 by means of asuitable claw ordog-clutch connection. However, there is nothing to prevent the slidevalve 32 from being driven by other suitable means, and hence thetransmission of motion from'the distributing slide valve 9 is only to beconsidered as an example of realization, which is illustrated on theaccompanying drawings wherein Figs. 1 and 1a show both a longitudinaland a transverse section of a previously known arrangement;

The case or shell 29 of the slide valve for distributing air totheexhaust valves (hereinafter called the second slide valve) is, asalready mentioned, connected to the case 8 of the distributing valve 9(called the first distributing valve). In the distributing valve 9 thereis secured a carrier in the form of a shaft 3| extending into the seconddistributing valve 32 .and provided with a claw 33 (Figures 2 to 4),which is adapted, upon the rotation of the shaft in the one or the otherdirection, to cooperate with or press against the one or the other sideof a corresponding claw 34 located on the second distributingvalve 32.The mutual positions of the claws 33 and 34 are shown in the positionfor forward movement in Figure 3 and in that for reverse movement inFigure 4. As will be apparent from these figures,

the claw 33 of the shaft 3| may be turned through an angle of 180 inrelation to the claw 34 of the second distributing valve 32, which takesplace when the direction of rotation is changed from ahead" to "reverseor vice versa.

The compressed air conveyed from the air admission valve 4 through thepipe 1 to an axial bore (dotted lines) in the first distributing valve 9continues to the second distributing valve 32 through a bore 35 (Figure2) in the carrier shaft 3|. From the bore 35 passages 39 and 31 branchofi, which passages are adapted to register with passages 38 and"39provided in the second distributing valve 32, so that air can enter intorecesses 40, 4| in the valve 32. Upon rotation of the valve the edges ofthe recesses 49, 4| will respectively open and shut passages 42, 43, 44and 45 provided in the housing or shell 29 of the second distributingvalve 32.

From the passages 42, 43, 44 and 45 the air is conducted through pipes49 to corresponding exhaust valves 59. Each exhaust valve is maintainedopen as long as compressed air is admitted through conduit 49. Theexhaust valve is shut, on the other hand, by the pressure in conduit 49being released when the compressed air is discharged from the samethrough one of the recesses 41, 41a (Figure 2), when the seconddistributing valve 32 is in the position for forward or reversemovement, the passages 46 in the valve case then registering with therecess 41a. (for forward movement) or the recess 41 (for reversemovement). The passages 36, 33 and the recess 49 form a connection forthe compressed air upon the reversal from reverse to ahead, and thepassages 31, 39 and the recess 4| a connection for the compressed airupon the reversal from ahead" to "reverse. In order that the drawingsshall not become too complicated, only the ans-1.57s

passages 31, 39 and the recess 4| have been shown in Figures 3 and 4.The passages 39, 33 and the recess 49 are situated on the opposite sidein relation to the passages 31, 39 and the recess 4|. Moreover, theslide valve 32 as shown in Figure 2 occupies an intermediate position(the stop position).

The reversal from full speed ahead" to full speed reverse takes place inthe following manner:

(l) The control lever I3 is moved from the for- "ward position directlyinto the reverse position.

Due to this the passages 31, 39 and 4| in the slide valve 32 are set insuch positions as to register 1 with the passages 42, 43, 44 and 45 inthe valve case 20.

31 in the carrier shaft 3| registers with the pas-' sage 39 in thesecond distributing valve 32 (see Figure 3), so that compressed air issupplied to the exhaust valves 5|), which on account of the abovementioned adjustment takes place at the moment when the correspondingcrank passes the upper dead center. Due to compressed air admitted intothe cylinders through the starting valves, there will be obtained agreater strength of compression than normally, causing the engine to berapidly braked through the increased compression in one cylinder afterthe other. However, the compressed air will not get an opportunity ofexpanding, but is allowed to escape through the exhaust valves 59 whenthe crank has passed the upper dead center. When the engine has as aresult come to rest, it immediately starts in the opposite direction,driven by air from the starting valves At this instant the slide valve32 comes to a stop on account of the friction against the valve case,and continues to stand still until the claw 33 has turned throughanangle of 180 and carries the claw 34 with it in the new direction ofrotation (see Figure 4). By this means the passage 31 is evidentlyturned through an angle of 180 and communicates no longer with thepassage 39 in the slide valve 32 (see Figure 4). By this means the airis shut off from the exhaust valves 50, and hence these cease to operateand are closed under spring action. The exhaust valves 50 may be of sucha nature that at the same time they act as safety valves.

According to the embodiment of the exhaust valves shown in Figure 3these valves communicate via passages 53 with passages 56 provided inthe cylinder cover, for example. In the valve cage there is slidablyarranged a valve stem 51, the upper end 52 of which normally forms asealing join against a valve seat under the influence of a spring 59. Apassage 54 leads from the valve seat to a silencer for example. Inconnection with the valvestem 51 there is provided a plunger 59, abovewhich compressed air is introduced through the previously mentioned pipe49, said air efl'ecting the opening of the exhaust valve, so

that air compressed in the engine cylinder is discharged into theatmosphere at the end of the compression stroke. As appears from theforegoing the exhaust valves are evidently operated pneumatically, i. e.arranged to be started into operation by means of compressed airadmitted. In conjunction with the reversal the use of such valvesinvolves certain advantages, and the pneumatic valve control of theexhaust valves forms, therefore, an essential part of the invention.

As already pointed out the drawings illustrate only an example ofrealization, the various parts of which may be altered in many differentways within the scope of the invention.

We claim:

1. A reversible internal combustion engine of the kind in which air iscompressed in the engine cylinders including pneumatically actuatedrelief valves for discharging air compressed in said cylinders,distributing valve means mechanically operated from the engine forautomatically supplying compressed air to said relief valves at timedintervals to open the same at the ends of the compression strokes of therespective cylinders, and engine control means including an operatingmember shiftable to forward and reverse positions, said distributingvalve means including mechanism operable to continue to supplycompressed air to said relief valves after shifting of said member fromone of said positions only so long as the engine continues to rotate inthe same direction as that occurring prior to the shifting of saidmember.

2. A reversible internal combustion engine of the kind in which air iscompressed in the engine cylinders, including pneumatically actuatedrelief valves for discharging air compressed in the engine cylinders toa zone of low pressure, and

means including an engine driven distributing valve for automaticallysupplying compressed air at timed intervals to said relief valves toopen the same at the ends of the compression strokes of the respectivecylinders, said relief valves including pressure responsive partsopening under the influence of excessive compression pressures in saidcylinders, whereby to cause the relief valves to act as safety valvesfor said cylinders.

3. A reversible internal combustion engine of the kind in which air iscompressed in the engine cylinders, including pneumatically actuatedrelief valves for discharging air compressed in the engine cylinders,distributing valve means for supplying compressed air to said reliefvalves to open the same at the ends of the compression strokes of therespective cylinders, starting valves for the engine cylinders,distributing valve means for supplying compressed air to said startingvalves, means for mechanically operating both of said distributing valvemeans from the engines, a control member for controlling the directionof operation of the engine, and means for adjusting the position of saiddistributing valve means in response to movement of said control member.

4. A reversible internal combustion engine of the kind in which air iscompressed in the engine cylinders, including pneumatically actuatedrelief valves for discharging air compressed in the engine cylinders,starting valves for the engine cylinders, engine driven distributingvalve means for supplying compressed air to said starting valves, enginedriven distributing valve means for supplying compressed air to saidrelief valves to open the same at the ends of the compression strokes ofthe respective cylinders, an engine control member for shifting thepositions of said distributing valve means, and a lost motion connectionbetween the engine and the second mentioned distributing valve meansoperative upon reversal of the direction of rotation of the engine tocut off the supply of compressed air distributed by the second mentioneddistributing valve means to said relief valves.

5. A reversible internal combustion engine including air starting andreversing means, said means including an engine driven air distributingvalve and a. control member for shifting said distributing valve toforward and reverse positions, pneumatically actuated relief valves fordischarging to a zone of low pressure air compressed in the enginecylinders, a second distributing valve for delivering compressed air tosaid relief valves to open the same at the ends of the compressionstrokes of the respective cylinders, the second mentioned distributingvalve being shiftable in response to movement of said control memberfrom either of the terminal positions of the latter to cause said reliefvalves to open, and there being a lost motion driving connection betweenthe engine and the second mentioned distributing valve for causing thesupply of compressed air to saidrelief valves to be cut off uponreversal of direction of rotation of the engine after the shifting ofsaid control member to effect such reversal.

6. In areversible internal combustion engine, the combination with airstarting and reversing means including a control member shiftable toforward and reverse positions, of pneumatically actuated relief valvesfor the engine cylinders, and engine driven distributing valve means foradmitting compressed air to said relief valves to open the same at theends of the compression strokes of the respective cylinders, saiddistributing valve means being shiftable in response to movement of saidcontrol member from one of its terminal positions to cause said reliefvalves to be opened and being automatically responsive to reversal ofdirection of rotation of the engine subsequent to such shift of saidcontrol member to cut off the supply of operating air to said reliefvalves, whereby to effect automatic closure of the same upon suchreversal of the engine.

'7. A reversible internal combustion engine of the kind in which air iscompressed in the engine cylinders including pneumatically actuatedrelief valves for discharging air compressed in said cylinders,distributing valve means mechanically operated from the engine forautomatically supplying compressed air to said relief valves at timedintervals to open the same at the ends of the compression strokes of therespective cylinders, and engine control means including an operatingmember shiftable to forward and reverse positions, said distributingvalve means including mechanism operable to continue to supplycompressed air to said relief valves after shifting of said member fromone of said positions as long as the engine continues to rotate in thesame direction as that occurring prior to the shifting of said memberand means automatically actuated by reversal of the direction ofrotation of the engine after shifting of said member for causing thesupply of compressed air to said relief valves to be interrupted.

EDVIN' OSSIAN PARCIVAL THEGE. JOHN HENRY WILLIAM JULIUS.

